diff --git a/app/build-apk.sh b/app/build-apk.sh
index 4f9efc7..eae66a9 100755
--- a/app/build-apk.sh
+++ b/app/build-apk.sh
@@ -55,8 +55,41 @@ else
     exit 1
 fi
 
+# Dev Updater draws a real progress bar from "@@progress done/total" lines,
+# and ignores anything that isn't exactly that shape. Gradle can't be asked
+# for this directly: an init script using taskGraph.afterTask is rejected
+# outright by the configuration cache, and whenReady never fires on a cache
+# hit. --dry-run costs about a second, is cache-friendly, and prints one
+# ":task SKIPPED" line per task the real build will run, which is exactly
+# the total. The build then prints one "> Task :x" line per task as it
+# goes, so counting those against it is the whole mechanism.
+#
+# Task count is not time -- compileDebugKotlin and dexBuilder are most of
+# the wall clock -- so the bar moves unevenly. It is still counted work
+# rather than a guess at how long last time took.
+TASKS=$(./gradlew :androidApp:assembleDebug --dry-run --console=plain 2>/dev/null \
+    | grep -c '^:[A-Za-z:]* SKIPPED' || true)
+
 echo "==> Building"
-./gradlew :androidApp:assembleDebug
+if [ "${TASKS:-0}" -gt 0 ]; then
+    echo "@@progress 0/$TASKS"
+    DONE=0
+    ./gradlew :androidApp:assembleDebug --console=plain 2>&1 | while IFS= read -r line; do
+        echo "$line"
+        case "$line" in
+            "> Task "*)
+                DONE=$((DONE + 1))
+                echo "@@progress $DONE/$TASKS"
+                ;;
+        esac
+    done
+    # The pipeline's exit status is the shell's, not gradle's, so ask
+    # gradle again rather than reporting a failed build as a success. It is
+    # up to date by now, so this is a second or two.
+    ./gradlew :androidApp:assembleDebug --console=plain >/dev/null
+else
+    ./gradlew :androidApp:assembleDebug
+fi
 
 APK="$SCRIPT_DIR/androidApp/build/outputs/apk/debug/androidApp-debug.apk"
 echo